1. Field of the Invention
The present invention relates to a high-power and low-heat-generation three-phase magnetic generator that facilitates connection between a coil wire lead and an output lead.
2. Description of Related Art
A large-scale cruise motorcycle, which is used at the maximum rotation speed of an engine crankshaft of up to 10000 rpm, has many electric loads such as a headlight, a stereo and a heater. Therefore, the motorcycle uses a magnetization coil generator (alternator) that can provide a high output.
The generator is attached to a rear portion of the engine. The crankshaft accelerates and rotates the generator through a drive mechanism. A fan cools a power generation coil. Therefore, the generator can provide a high output.
Due to reasons related to an engine layout, it is required to use a high-power magnetic generator attached directly to the crankshaft instead of using the magnetization coil generator.
The magnetic generator can produce a high output by increasing an external diameter of a core and a volume of a rare-earth magnet. If an output current increases, temperature of the coil will increase. In order to reduce the coil temperature, the diameter of a coil wire has to be increased.
If the maximum output current is around 35A as before, the coil wire diameter of about 1.2 mm is sufficient. In this case, since the coil wire diameter is small, winding-start ends a, b, c and winding-finish ends a′, b′, c′ of the coil wires can be manually lead among coils 26 as shown in FIG. 28 in wave-like shapes and can be gathered at a point A shown in FIG. 27 after the coil wires are wound as shown in FIG. 30. Then, the six coil wire leads 25 (the winding-start ends a, b, c and the winding-finish ends a′, b′, c′) can be manually bundled at the point A. Then, the coil wire leads 25 gathered at the point A and output leads 41 are put into cylindrical sleeves 61 and fixed at a position B shown in FIG. 27, and are connected with each other by soldering. Then, the connected portions are covered by a protection tube 42, and the three output leads 41 are bundled with a clip 43. The bundled output leads 41 are fixed to a core 21 by threading a screw 44.
If the output current is 40A or over, the diameter of the wire of the coil 26 needs to be 1.3 mm or over. Thus, the coil wire diameter becomes thick. In such a case, if the coil wire leads 25 are lead and gathered to the point A manually, or the coil wire leads 25 are wound around each other and bundled to fix the coil wire leads 25 to the coil 26 manually as shown in FIGS. 27 and 28, there is a possibility that hands of a worker will become sore.
The coil wire leads 25 are gathered and fixed at the point A in order to reduce variation in a dimension L4 from the clip 43 to a grommet 62 shown in FIG. 29 after the coil wire leads 25 and the output leads 41 are connected. If the coil wire leads 25 are not fixed to the coil 26 at the point A, the coil wire leads 25 will easily move. As a result, the dimension L1 shown in FIGS. 28 and 29 will vary. The length L2 of the output lead 41 is determined in advance when the lead 41 is manufactured. If the dimension L1 varies, the dimension L3 between the clip 43 and the tip end of the connected portion will vary. Accordingly, the dimension L4 will vary. If the dimension L4 varies, a problem will be caused when the grommet 62 is attached to an engine cover 300 shown in FIG. 26. If the dimension L4 is too short, the grommet 62 cannot be fit into a groove 302 of the engine cover 300. If the dimension L4 is too long, a slack between the grommet 62 and the clip 43 becomes large, and a lead cover 63 will be pushed toward a rotor 1. As a result, there is a possibility that the lead cover 63 will contact an outer periphery of the rotor 1.
If the coil wire leads 25 are not fixed to the coil 26, the coil wire leads 25 will easily vibrate. Thus, vibration-resistance of the coil wire leads 25 will be deteriorated. Therefore, the coil wire leads 25 are fixed to the coil 26 to ensure the vibration-resistance of the coil wire leads 25.
If the output current is increased, the output leads 41 also have to be made thicker. In such a case, if two thick coil wire leads 25 and one thick output lead 41 are connected with each other, rigidity of the connected portion will increase. If the connected portion is soldered manually or fixed with the clip 43 manually, there is a possibility that the hands of the worker will become sore because the coil wire leads 25 are rigid and hard to move.
JP-A-2003-259588 describes a structure in which a terminal is knocked into a bobbin and a coil wire lead and an output lead are connected with each other through the terminal. However, this structure has the following defects. That is, in order to insert the bobbin into a core, a clearance is necessary in consideration with a dimensional tolerance. In addition, in order to form the bobbin, a thickness of about 0.7 mm is necessary. Therefore, heat conduction from the bobbin to the core is poor. Accordingly, heat radiation from the coil to the core is small, and the coil temperature will increase. A space for winding the coil wire is reduced, and only a thin coil wire can be wound. Accordingly, the coil temperature will increase. The terminal is just press-fit into a resin. Therefore, the terminal cannot endure vibration of the thick coil wire lead or the thick output lead. As a result, there is a possibility that the terminal will slacken.